This example demonstrates a node-and-link network visualization using D3.js v6. It renders nodes as steelblue circles and links as gray lines within an SVG container. The code includes a force-directed layout with `d3.forceSimulation`, `d3.forceLink`, `d3.forceManyBody`, and `d3.forceCenter` to position elements. The nodes and links are sample data, and the interaction includes drag-and-drop functionality via `d3.drag`, with positions updated on each simulation tick. Links connect nodes by id, and the rendering approach uses SVG.